package sw.util;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
/**
 * 验证码
 * @author LR
 *
 */
public class Captcha {
	// 图片的宽度
		private int width = 160;
		// 图片的高度。
		private int height = 40;
		// 验证码字符个数
		private int codeCount = 4;
		// 验证码干扰线数
		private int lineCount = 20;
		// 验证码
		private String code = null;
		// 验证码图片Buffer
		private BufferedImage image = null;
		Random random = new Random();

		public Captcha() {
			generate();
		}

		public Captcha(int width, int height) {
			this.width = width;
			this.height = height;
			generate();
		}

		public Captcha(int width, int height, int codeCount) {
			this.width = width;
			this.height = height;
			this.codeCount = codeCount;
			generate();
		}

		public Captcha(int width, int height, int codeCount, int lineCount) {
			this.width = width;
			this.height = height;
			this.codeCount = codeCount;
			this.lineCount = lineCount;
			generate();
		}

		// 生成图片
		private void generate() {
			int fontWidth = width / codeCount;// 字体的宽度
			int fontHeight = height - 5;// 字体的高度
			int codeY = height - 8;
			// 图像buffer
			image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
			Graphics g = image.getGraphics();
			//Graphics2D g = buffImg.createGraphics();
			// 设置背景色
			g.setColor(getRandColor(200, 250));
			g.fillRect(0, 0, width, height);
			// 设置字体
			//Font font1 = getFont(fontHeight);
			Font font = new Font("Fixedsys", Font.BOLD, fontHeight);
			g.setFont(font);
			// 设置干扰线
			for (int i = 0; i < lineCount; i++) {
				int xs = random.nextInt(width);
				int ys = random.nextInt(height);
				int xe = xs + random.nextInt(width);
				int ye = ys + random.nextInt(height);
				g.setColor(getRandColor(1, 255));
				g.drawLine(xs, ys, xe, ye);
			}
			// 添加噪点
			float yawpRate = 0.01f;// 噪声率
			int area = (int) (yawpRate * width * height);
			for (int i = 0; i < area; i++) {
				int x = random.nextInt(width);
				int y = random.nextInt(height);
				image.setRGB(x, y, random.nextInt(255));
			}
			String str1 = randomStr(codeCount);// 得到随机字符
			this.code = str1;
			for (int i = 0; i < codeCount; i++) {
				String strRand = str1.substring(i, i + 1);
				g.setColor(getRandColor(1, 255));
				// g.drawString(a,x,y);
				// a为要画出来的东西，x和y表示要画的东西最左侧字符的基线位于此图形上下文坐标系的 (x, y) 位置处
				g.drawString(strRand, i * fontWidth + 3, codeY);
			}
		}

		// 得到随机字符
		private String randomStr(int n) {
			String str1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
			String str2 = "";
			int len = str1.length() - 1;
			double r;
			for (int i = 0; i < n; i++) {
				r = (Math.random()) * len;
				str2 = str2 + str1.charAt((int) r);
			}
			return str2;
		}

		// 得到随机颜色
		private Color getRandColor(int fc, int bc) {// 给定范围获得随机颜色
			if (fc > 255)
				fc = 255;
			if (bc > 255)
				bc = 255;
			int r = fc + random.nextInt(bc - fc);
			int g = fc + random.nextInt(bc - fc);
			int b = fc + random.nextInt(bc - fc);
			return new Color(r, g, b);
		}

		/**
		 * 产生随机字体
		 */
		private Font getFont(int size) {
			Random random = new Random();
			Font font[] = new Font[5];
			font[0] = new Font("Ravie", Font.PLAIN, size);
			font[1] = new Font("Antique Olive Compact", Font.PLAIN, size);
			font[2] = new Font("Fixedsys", Font.PLAIN, size);
			font[3] = new Font("Wide Latin", Font.PLAIN, size);
			font[4] = new Font("Gill Sans Ultra Bold", Font.PLAIN, size);
			return font[random.nextInt(5)];
		}

		// 扭曲方法
		private void shear(Graphics g, int w1, int h1, Color color) {
			shearX(g, w1, h1, color);
			shearY(g, w1, h1, color);
		}

		private void shearX(Graphics g, int w1, int h1, Color color) {
			int period = random.nextInt(2);
			boolean borderGap = true;
			int frames = 1;
			int phase = random.nextInt(2);
			for (int i = 0; i < h1; i++) {
				double d = (double) (period >> 1)
						* Math.sin((double) i / (double) period
						+ (6.2831853071795862D * (double) phase)
						/ (double) frames);
				g.copyArea(0, i, w1, 1, (int) d, 0);
				if (borderGap) {
					g.setColor(color);
					g.drawLine((int) d, i, 0, i);
					g.drawLine((int) d + w1, i, w1, i);
				}
			}
		}

		private void shearY(Graphics g, int w1, int h1, Color color) {
			int period = random.nextInt(40) + 10; // 50;
			boolean borderGap = true;
			int frames = 20;
			int phase = 7;
			for (int i = 0; i < w1; i++) {
				double d = (double) (period >> 1)
						* Math.sin((double) i / (double) period
						+ (6.2831853071795862D * (double) phase)
						/ (double) frames);
				g.copyArea(i, 0, 1, h1, 0, (int) d);
				if (borderGap) {
					g.setColor(color);
					g.drawLine(i, (int) d, i, 0);
					g.drawLine(i, (int) d + h1, i, h1);
				}
			}
		}

		public void write(OutputStream sos) throws IOException {
			ImageIO.write(image, "png", sos);
			sos.close();
		}

		public BufferedImage getImage() {
			return image;
		}

		public String getCode() {
			return code.toLowerCase();
		}
}
